Method for the production of the film tube bag and the vertical form fill seal packaging machine to implement the method

ABSTRACT

A method of a film tube bag production includes shaping longitudinal foldings ( 6 ) on packing film ( 8 ), and attaching a secondary all-round closure ( 5 ) on an inner side ( 21 ) of the packing film ( 8 ). Its longitudinal axis is perpendicular to the longitudinal axis of the longitudinal foldings ( 6 ). The length of the secondary all-round closure ( 5 ) corresponds to the size of an inside circumference of the bag ( 1 β). The method further includes shaping of the packing film ( 8 ) into the form of the film tube, closing the film tube and creating the folded flat quadrilateral bottom ( 3 ), and filling the bag and forming the upper cross seam ( 2 ).

RELATED APPLICATION

This application claims priority to PCT Int'l. App. No. PCT/CZ2015/000025, filed 25 Mar. 2015, which claims priority to CZ Patent Application No. PV 2014-199, filed 27 Mar. 2014. Each of these priority applications is expressly incorporated by reference herein in its entirety.

TECHNICAL FIELD

The proposed invention concerns a method for the production of a film bag, a film bag with a flat bottom, in particular, with longitudinally sealed reinforcing foldings, and the packaging machine intended for the production of this film bag.

BACKGROUND ART

Assorted types of film bags have been available, which are used to pack small wares and food as namely spices, sweets, etc. It is a question of a film tube bag with a folded flat quadrilateral bottom and with welded longitudinal foldings, for instance. The bottom comprises a lower cross seam. The bag is equipped with a plastic zipper closure in the upper part of its inner body, said zipper comprising two parts. The zipper closure represents a secondary closure. The primary closure is formed by an upper cross seam and is situated above the secondary closure.

First of all, a user removes the primary closure formed as an upper cross seam to open such a bag. Then, he opens the bag in the way to draw out mutually connected parts of the zipper closure from each other. Thus, the user has a disposal of a round hole to enter the bag at maximum, the space of which results merely from the openable length of the closed zipper closure—the closure has both its parts mutually welded at the ends for the reason of its easier locking, in principle.

The method for production of such a bag is performed so that the packing film is wound up to form a film tube on which the longitudinal foldings are shaped and sealed. Thereafter, the film tube is insulated by the lower cross seam in its bottom part, whereas the folded bottom of the bag is formed simultaneously.

The two-piece zipper closure is applied to the bag in the following way. First of all, both parts of the zipper closure, which are mutually inserted into each other, are welded by its single part onto the packing film, which shall subsequently be shaped as a film tube with longitudinal foldings that are sealed, thereat. The zipper closure must be placed on the packing film in order to enable its positioning on the resulting bag on the inner surface of the front, or rear side of the bag. Therefore, the zipper closure is shorter a bit than the width of the bag side to which it is applied to, in this case. When closing the bag by the top cross seal the other part of the zipper closure, so far not welded to the packing film, shall partially be welded to the inner surface of the opposite side of the bag, and partially to both side interlayer papers, formed at the bag production.

Substantive disadvantage of this particular favourite, rather a good looking, and a very well standing bag is considered to be a less spacious area of the discharge opening to the bag. This causes a significant problem at smaller bags, in particular.

DISCLOSURE OF THE INVENTION

The method for the film tube bag production is the subject matter of the invention. This method comprises the following operations:

Shaping and fixing longitudinal foldings on the outer side of the packing film;

Fixing the secondary closure on the inner side of the packing film. The longitudinal axis of the secondary closure is perpendicular to the longitudinal axis of the longitudinal foldings. The secondary closure is positioned so that it is located under the upper cross seam on the finished bag and the length of the applied secondary closure corresponds to the size of the inside circumference of the bag. It means that the length of the secondary closure reaches its maximum potential. In terms of an optimum case, it is identical to the size of the inside circumference of the bag. The secondary closure with a reasonably shorter length is used to be respected in practice in consideration of necessary manufacturing tolerance. Thus, the beginning and the end of the secondary closure are prevented from overlapping each other in the finished bag, which is unacceptable regarding the requested tightness. A very small incidental spacing between the beginning and the end of the secondary closure is generally not considered a defect;

Shaping of the packing film with the parallel longitudinal foldings into the form of the film tube;

Closing the film tube with the longitudinal seam parallel with longitudinal foldings;

Creating the folded flat quadrilateral bottom with the lower cross seam;

Filling the bag with the packed goods;

Creating the upper cross seam on the side of the bag opposite the folded flat quadrilateral bottom;

Separating the filled bag from the film tube.

The secondary closure is composed of a one-piece zipper closure in the convenient embodiment of the invention, in particular.

The secondary closure can be composed of a double-sided adhesive tape in another convenient embodiment. In that case the side of the adhesive tape glued on the inner side of the bag indicates a higher binding property than the other side. The adhesive layer situated on the side of the strip facing inward of the bag enables to separate the strips repeatedly and connect them again, and thereby the sides of the bag, as well.

The secondary closure is composed of a spread of a permanent adhesive in another convenient embodiment of the invention. That enables to separate the inner sides of the bag repeatedly and connect them again at the point of the secondary closure.

First of all, three longitudinal foldings are formed only in certain cases (e.g. a neater bag appearance, a simplification of one of the production steps). The fourth longitudinal folding is formed by a latterly formed longitudinal seam. It means that three corners of the bag are equipped with longitudinal folding and the fourth corner of the bag with the longitudinal seam. Thanks to this fact, the longitudinal seam does not have to be positioned in a certain (in the rear side, generally) side of the bag.

It is an advantage to apply the vertical form fill seal packaging machine in accordance with the related invention for the afore-mentioned method of the production. The machine comprises (in the direction of the packing film movement) the following: a device for packing film unwinding, which is followed by the device for shaping and fixing longitudinal folding on the packing film. It is followed by a device for an application of the one-piece secondary closure on the packing film with formed longitudinal foldings. Thereinafter, a forming collar, a filling tube as well as a longitudinal sealing jaw to manufacture the longitudinal seam follow. There is a device for the packing film feed leading through the forming collar in the space below the forming collar. Furthermore, it is followed by a device enabling to form the flat bottom of the bag, and lateral sealing and separating jaws to manufacture the cross seam, and to separate the filled bag.

The packing film runs through all mentioned components of the machine where it is gradually processed in the form of a filled film tube bag closed by the primary and secondary closures. A stable bag is elaborated thanks to the previously mentioned production method including advantages manufactured by the described machine, equipped with the secondary closure, which has a disposal of a large opening to access the inwards of the bag. The area of such an opening stems from the circumference of the whole bag and is on order of tens of percentages higher than at the application of a common two-piece zipper closure.

BRIEF DESCRIPTION OF DRAWINGS

Exemplary implementation of the submitted invention shall be described with reference to drawings where the below mentioned figures show the details of

FIG. 1 The film tube bag with a flat bottom, secondary closure and longitudinal reinforcing foldings;

FIG. 2 The layout of the vertical form fill seal packaging machine with the device for an application of the secondary closure.

BEST MODE FOR CARRYING OUT THE INVENTION

Exemplary method for the film tube bag 1 production comprises the following sequential consecutive operations:

Shaping and fixing three longitudinal foldings 6 on the outer side of the packing film 8;

Attaching the all-round secondary closure 5, which longitudinal axis is perpendicular to the longitudinal axis of longitudinal foldings 6 on the inner side of the packing film 8. The all-round secondary closure 5 is situated in the way that it is placed inside the finished bag below the upper cross seam 2. In this case, the secondary closure 5 is formed by a one-piece zipper closure and the length of the applied secondary all-round closure 5 corresponds with the size of the bag inside circumference;

Shaping of the packing film 8 together with the parallel longitudinal foldings 6 into the form of the film tube;

Closing of the film tube with the longitudinal seam 7 parallel with longitudinal foldings 6. In this case, the longitudinal seam 7 is located in one of the corners of the bag 1, and it forms the fourth longitudinal folding 6, simultaneously;

Forming the folded flat quadrilateral bottom 3 together with the lower cross seam 4;

Filling the bag 1 with the packed goods;

Forming the upper cross seam 2 on the side of the bag 1 opposite the folded flat quadrilateral bottom 3,

Separating the filled bag 1 from the film tube.

The vertical form fill seal packaging machine used for the above described method for the film tube bag production comprises the device 11 for the unwinding the packing film 8 followed by the device 12 for welding longitudinal foldings 6 on the packing film 8. Thereinafter, another device 17 shall be integrated in the machine with the aim to apply a one-piece secondary all-round closure 5 on the packing film 8 with formed longitudinal foldings 6. It is followed by the forming collar 13, filling tube 14 and the longitudinal sealing jaw 15 forming the longitudinal seam 7 and the device 19 for the packing film 8 feed and then the device 18 for forming the flat bottom 3 of the bag 1 as well as the lateral sealing and separating jaws 16 to manufacture the cross seam 2, 4, and to separate the filled bag 1.

Exemplary embodiment shall be depicted in FIG. 1 and FIG. 2.

LIST OF REFERENCE NUMBERS

-   1—Bag -   2—Upper Seam -   3—Bottom -   4—Lower Seam -   5—Secondary All-round Closure -   6—Longitudinal Folding -   7—Longitudinal Seam -   8—Packing Film -   11—Device for Packing Film Unwinding -   12—Device for Shaping and Fixing Longitudinal Foldings -   13—Forming Collar -   14—Filling Tube -   15—Longitudinal Sealing Jaw -   16—Lateral Sealing and Separating Jaws -   17—Device for the Application of One-piece Secondary All-round     Closure -   18—Device for the Flat Bottom Formation -   19—Device for the Packing Film Feed -   20—Outer Side of the Packing Film -   21—Inner Side of the Packing Film 

1. The method for the production of a film tube bag comprising the following operations: shaping and fixing longitudinal foldings (6) on an outer side (20) of a packing film (8), shaping of the packing film (8) with parallel longitudinal foldings (6) into a form of a film tube, closing of the film tube by a longitudinal seam (7) parallel with the longitudinal foldings (6), forming a folded flat quadrilateral bottom (3) with a lower cross seam (4), filling the bag (1) with packed goods, forming an upper cross seam (2) on a side of the bag (1) opposite the folded flat quadrilateral bottom (3), separating the filled bag (1) from the film tube, after shaping and fixing the longitudinal foldings (6), fixing a secondary closure (5) on an inner side (21) of the packing film (8), which longitudinal axis is perpendicular to a longitudinal axis of the longitudinal foldings (6) prior to shaping the packing film (8) into the film tube, whereas the secondary closure (5) is positioned so that it is located on the finished film tube bag below the upper cross seam (2) where the length of the applied secondary all-round closure (5) corresponds to a size of an inside circumference of the film tube bag (1).
 2. The method for the production of the film tube bag according to the claim 1, wherein the secondary all-round closure (5) is formed of a one-piece zipper closure.
 3. The method for the production of the film tube bag according to the claim 1, wherein the secondary all-round closure (5) is formed of a double-sided adhesive tape where a side of the tape glued on the inner side of the bag (1) indicates a higher binding property than the other side.
 4. The method for the production of the film tube bag according to the claim 1, wherein the secondary all-round closure (5) is formed by a spread of a permanent adhesive.
 5. The method for the production of the film tube bag according to claim 2, wherein three longitudinal foldings (6) are formed primarily, and a fourth longitudinal folding (6) is formed by the longitudinal seam (7) formed afterwards.
 6. A vertical form fill seal packaging machine according to the method of the film tube bag production of claim 1 comprising: a device (11) for unwinding the packing film (8), where a device (12) is situated behind the device (11) for shaping and fixing longitudinal foldings (6) on the packing film (8); a forming collar (13); a filling tube (14); a longitudinal sealing jaw (15) applicable to the formation of the longitudinal seam (7); a device (19) for feeding the packing film (8) through the forming collar (13), and thereinafter a device (18) for the formation of the flat bottom (3) of the bag (1); a lateral sealing and separating jaws (16) to form a cross seam (2, 4), and applicable to the separation of the filled bag (1); and a device (17) for the application of the one-piece secondary all-round closure (5) on the inner side (21) of the packing film (8) with formed longitudinal foldings (6) located within the space between the device (12) for shaping and fixing the longitudinal foldings (6) and the forming collar (13).
 7. The method for the production of the film tube bag according to claim 3, wherein three longitudinal foldings (6) are formed primarily, and a fourth longitudinal folding (6) is formed by the longitudinal seam (7) formed afterwards.
 8. The method for the production of the film tube bag according to claim 4, wherein three longitudinal foldings (6) are formed primarily, and a fourth longitudinal folding (6) is formed by the longitudinal seam (7) formed afterwards. 